Electrotransport adhesive

Abstract

PCT No. PCT/US90/00727 Sec. 371 Date Aug. 6, 1991 Sec. 102(e) Date Aug. 6, 1991 PCT Filed Feb. 8, 1990.A two phase adhesive matrix for use in an electrically powered iontophoretic delivery device is provided. The adhesive matrix comprises an adhesive hydrophobic polymer phase and about 15 to 60 wt % on a dry weight basis of a hydrophilic polymer phase distributed through the hydrophobic polymer phase. The hydrophilic phase forms upon hydration an interconnecting network of aqueous pathways for passage of the agent through the adhesive. The adhesive can be used to adhere an electrode assembly of an iontophoretic delivery device to a body surface such as skin or a mucosal membrane. Alternatively, the adhesive can be used to adhere together two or more elements of an iontophoretic delivery device.

What is claimed is: 
     
       1. A two phase adhesive matrix for use in an electrically powered intophoretic agent delivery device adapted to iontophoretically deliver an agent through a body surface, the adhesive comprising an adhesive hydrophobic polymer phase and about 15 to 60 wt % on a dry weight basis of a hydrophilic polymer phase distributed through the hydrophobic polymer phase, the hydrophilic phase forming upon hydration an interconnecting network of the hydrophilic polymer throughout the matrix, the network providing aqueous pathways for passage of the agent through the matrix. 
     
     
       2. The adhesive of claim 1, wherein the matrix comprises about 30 to 40 wt % on a dry weight basis of the hydrophilic polymer. 
     
     
       3. The adhesive of claim 1, wherein the adhesive is capable of absorbing about 7 to 80 wt % water based on the total weight of the adhesive. 
     
     
       4. The adhesive of claim 1, wherein the hydrophilic polymer is selected from the group consisting of polyacrylamide, cross-linked dextran, polyvinylalcohol, starch-graft-poly(sodium acrylate-co-acrylamide) polymers, hydroxypropylmethylcellulose, low-substituted hydroxypropylcellulose. cross-linked Na-carboxymethylcellulose, polyhydroxyethyl methacrylate, blends of polyoxyethylene and polyethylene glycols with polyacrylic acid, polyethylene oxides and cross-linked polyvinyl pyrrolidone. 
     
     
       5. The adhesive of claim 1, wherein the hydrophilic polymer is in the form of particles having a particle size of up to about 180 μm. 
     
     
       6. The adhesive of claim 5, wherein the hydrophilic particles have a particle size of up to about 35 μm. 
     
     
       7. The adhesive of claim 1, the adhesive exhibiting a specific resistance of less than about 0.33 kohm-cm 2  per mil thickness of adhesive. 
     
     
       8. The adhesive of claim 1, wherein the hydrophobic polymer is selected from the group consisting of acrylate adhesives and silicone adhesives. 
     
     
       9. The adhesive of claim 1, wherein the hydrophobic polymer phase is rendered adhesive by adding thereto a tackifying resin. 
     
     
       10. The adhesive of claim 9, wherein the hydrophobic polymer is selected from the group consisting of poly(styrene-isoprene-styrene) block copolymers, ethylene vinyl acetate polymers, plasticized and unplasticized polyvinylchloride, natural and synthetic rubber, C 2  -C 4  polyolefins, polyethylene, polyisoprene, polyisobutylene and polybutadiene. 
     
     
       11. The adhesive of claim 9, wherein the tackifying resin is selected from the group consisting of fully hydrogenated aromatic hydrocarbon resins, hydrogenated esters and low molecular weight grades of polyisobutylene. 
     
     
       12. The adhesive of claim 1, wherein the adhesive matrix also contains at least a portion of the agent to be delivered. 
     
     
       13. The adhesive of claim 1, wherein the agent comprises a drug. 
     
     
       14. The adhesive of claim 13, wherein the drug comprises a water soluble drug salt. 
     
     
       15. The adhesive of claim 1, wherein the agent comprises an electrolyte. 
     
     
       16. The adhesive of claim 15, wherein the electrolyte comprises a water soluble electrolyte salt. 
     
     
       17. The adhesive of claim 1, wherein the hydrophilic polymer is a hydrogel. 
     
     
       18. The adhesive of claim 1, wherein the hydrophilic polymer is a cellulosic derivative.